The invention relates generally to measuring devices and more specifically to a device having a digital readout and three sets of specially adapted components to make center-to-center, center-to-edge and edge-to-edge measurements.
While quality control is the contemporary focus of manufacturing, obtaining accurate measurements of components is clearly the focus of quality control. Stated somewhat differently, without the proper measurement equipment and techniques, the expectation of quality goods may be nothing more than an expectation.
In manufacturing facilities, machine shops and repair depots, linear measurements are generally accomplished with micrometers, scales, calipers and vernier calipers. These devices typically provide accurate measurements between two flat or curved surfaces. When the component or particular feature of a component to be measured is more complex, adaptations of the foregoing delineated devices may be utilized. For example, U.S. Pat. No. 2,693,033 teaches several basic mechanical devices which utilize either a pair of cones, one of which is slidable along a linear scale, or a slidable cone and fixed edge to measure either center-to-center or center-to-edge distances. U.S. Pat. No. 3,289,307 teaches a similar distance gauge wherein a first cone affixed to one end of a scale and a second cone and vernier which are slidable along the scale provides center-to-center distance measurement. Portions of the center measuring cones nest to facilitate measurement of small center-to-center distances.
In U.S. Pat. No. 3,805,397, a pair of perpendicularly oriented scales having edge engaging sliders may be utilized to find the center of circular objects. U.S. Pat. No. 4,731,931 teaches another mechanical distance measuring device utilizing a dial indicator. The basic device utilizes inside and outside calipers to which cone centering devices may be attached to permit center-to-center measurement of apertures.
More recent devices of this type include electronic digital readouts. For example, U.S. Pat. No. 4,229,883 discloses a relatively conventional hand-held caliper for taking inside and outside diameter measurements. Electronic scaling of the translation of the slider is achieved by light emitting and receiving elements which cooperate with a scale on the beam of the caliper assembly. U.S. Pat. No. 4,566,199 teaches a device similar to a conventional sliding caliper which further includes a digitally electronic readout and spring biased conical member which cooperates with either a straight edge to measure edge-to-center distances or a second cone to measure center-to-center distances between circular apertures.
U.S. Pat. No. 4,612,656 presents an inside and outside caliper apparatus having a digital readout and output port which may drive a printer or other recording device. U.S. Pat. No. 4,972,603 comprises a pair of parallel, spaced-apart rails, a measuring head having a digital readout and adjustable elements such as caliper arms and stops which adapt the device to a large number of measurement tasks.
From the foregoing review, it is apparent that improvements in he art of linear measurement devices are both possible and desirable.